Refillable gas tanks (e.g., oxygen tanks) typically have a valve integrated therein with an inlet through which they are filled with a gas and an outlet through which the gas is dispensed. Such valves are generally positioned or biased (e.g., using a spring) into an open position. However, when the gas tank needs to be refilled, the valve must be closed or sealed to prevent recharging gas from leaking from the tank. Currently, the valve is manually manipulated or temporarily removed and replaced with an outlet seal. Manual manipulation of the valve requires additional time and care, while replacing the valve with a seal exposes the tank to environmental contaminants that can be of great concern in the case of oxygen tanks or tanks that contain breathing gasses. Additionally, certain applications do not permit manual manipulation of cylinder valves thereby necessitating some other process to re-seat the valve.